<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            width: 200px;
            height: 200px;
            background-color: red;
            border: 1px dashed #000;
        }
    </style>
</head>

<body>
    <!-- 
        边框
        solid
        dashed
        dotted
     -->
    <div class="box"></div>
</body>

</html>